nc NOTOGAEA, NEOGAEA, AND ARCTOGAEA &5
the realm of Notogaea), and Madagascar; and finally, the realm
of Antarctogaea or Atheriogaea, which embraces JSTew Zealand,
the Antarctic continent., and a series of islands such as South
G-eorgia and Kerguelen, and possibly even the extreme south of
Patagonia. This latter quarter of the globe will need no further
reference, as it has no truly indigenous terrestrial mammalian
inhabitants. We cannot include the Bats in this statement, as
their distribution is due to different powers of extending their
range, and to different barriers from those which govern the
range of other groups of mammals.
(1) I^otogaea.1 This realm is characterised by the exclusive
possession of the Monotremes:—that is to say, one of the two
primary divisions of the Mammalia is ahsolutely restricted to
this area. It contains, moreover, the vast majority of the
Marsupials. Further, the realm of ISTotogaea is to be dis-
tinguished by the entire absence of the higher mammals, with
the exception of a few small Rodents. (The Bats are ignored
for the reasons stated, and the Dingo is believed to have been an
importation.) It cannot be disputed that this is a very distinctly-
marked area of the earth's surface.
(2) JSTeogaea. The continent of South America has no
Monotremes and only a few Marsupials, all of which, with the
exception of Caenolestes, belong to the Polyprotodont division of
that order, and to a peculiar family, Didelphyidae. The recent
discovery of other fossil Marsupials, however, to some extent
favours Huxley's view that 3STeogaea and ISTotogaea form one
realm as opposed to the rest of the world. Besides this,
IsTeogaea possesses the Edentata, which are found nowhere else ;----
that is, the division of the Edentata to which the name is
now restricted by some authorities. It is also characterised by
the nearly entire absence of the important order of Insectivora;
and, as minor marks of distinction, by the absence of Antelopes,
Oxen and Sheep, of the Ichneumon tribe, of Horses, and of Lemurs.
It has the exclusive possession of the Hapalidae and Cebidae,
and of several families of Rodents.
(3) Arctogaea. This vast realm is clearly capable of sub-
division into four regions, which will be considered in detail
later. In the meantime the points of likeness between these sub-
divisions is more marked than are either the resemblances or the
1 This term, ia sometimes used in a wider sense ; cf. voL viii. p. 74.